Apparatus for controllabley regulating temperature



March 5, 1929.

J. M. LARSON APPARATUS FOR CONTROLLABLY REGULATING TEMPERATURE Filed Oct. 1926 2 Sheets-Sheet 1 0%WP'W. XWM

March 5, 1929. J. M. LARSON 1,704,008

APPARATUS FOR CONTROLLABLYREGULATING TBIPERAZ'URE Filed Oct- 8. 192a smu -sheet 2 MMM - x A, Q@

Patented Mar. 5, .1929.

urrs S'lA-TES Jenn M. LARSON, or onrcao rnnrnors,

1,704,008 PATENT QFFIQE.

AssIo on 'ro NATIONAL REGULATOR 00.,

0F GHECAGO, ILLINOIS, A CORPORATION OF ILLINOIS,

ATEPARATUS FOR OONTROLLABLY BEGULATING TEMPERATURE.

Application filed OctoberS, was. sensin 140,232.

This invention relates to apparatus for controllably regulating temperature, and more specifically concerns combined. thermostatic control air conditioning and circulating apparatus and oi" heatsradiating units.

In rooms, particularly such as otlices and schoolsrooms, it is highly desirable that a desired uniform temperature be maintained and a plentiful supply of fresh air be circulated without requiring constant attention and without subjecting the occupants of the iently adjusted or set at a selected tl'iermometric degree; which will operate automatically to control a combination of individually controllable elements forming; a part ojtthe atoresaid automatically controllable means; which possesses an unusually wide range of control line; effects; and which is so constructed that it may be readily taken apart ant re-assem-, bled, if desired, -for inspectlon or repairs, or

for any other reason.

In the drawings Figure l is a vertical sectional. view of an adjustable compound thermostatic controller constructed according to this invention is a horizontal sectionalview of one end-member serving; as the base of the controller, taken upon the line 2*2 of Fig. 1

Fig. 3 is a vertical sectional view of one form of a air conditioning; and circulating unit, having a novel arrangement of a plural ity of automatically controllable elements which are shown connected for combined con trol by the single compound thermostatic controller illustrated in Fig. 1; and

Fig. 4 is a vertical sectional view ofa modi tied formot air conditioning and. circulating unit, provided with a single automatically controllable element/{this view also showing, in elevation, at separately located, automatically controllable, supplemental or auxiliary heat-radiating unit, illustrating the connection of said element and said. heat-radiating unit for combined control by thealoresaid sp nglecompound thermostatic controller of In accordance with this invention, an ad justable compound thermostatic controller is provided for the combined control of an an rangjement of air dampers and heatmathwding units to the effect that,-with but a single con trol device, unusually wide ranges of control hog and regulating effects may be obtained, both in the degree of temperature desired to be produced and maintained and in the automatic compensation tor excessive variations in weather conditions. lVhile but one air conditioning and circulating unit and but one supplemental or auxiliary heat-radiating unit are shown and described herein in coir I nection with the single thermostatic control-. ler, it is to be understood that these units may be of different sizes and capacities and may be increased in number, either relatively or collectively, dependent upon various conditions which may exist, such for example, as

upon the size of the roomand its location with respect to the direction of the prevailing winds. However, the number, size, and place- I ment of the units are matters to be determined in the installation ofthe system and do not relate to the method of operation and control; It is sutlicient, in this respect,to state that one or more of such units may be controlledby a single compound thermostatic controller.

In order to give a better understanding of the purpose and use of the compound thermostaticcontroller, it maybe well, before describing its construction and operatiomto describe the automatically controllable elements which are connected therewith and controlled in operation thereby. i

Referring, first, to Fig. '3, it will be seen that the conditioning and circulatin unit therein shown compr" casing 1.,the in; terior of which. is d. lll into three communicatingchambers, and 4:. ,As shown in this view, the output chamber 2 and the intake chamber 4 are both mixing; chambers, the pair of air dampers for each of these chambers bein so connected that when one D l D damper of a pair is fully open,;the other damper of thatpair is tt'ullyclosed,and v versa, but, while this arrangement is generally preferable in order to maintain a con sizes oi"? the dampers may be different, and

ell)

tie.

their connections may be changed even to the degree in which one damper of a pair may be fully closed before the other damper of that pair begins to open. The communication of the intake chamber with the inte meoiate chamber 3 may be controlled by an electrically driven suction-tan 5, it being preferable, under certain conditions, to provic'e a forced draft. The intt-uinediate chamber 3 houses a. heat-radi ng unit (3, and the heating mcdium supplied to this unit n'iay be of any desired nature. n the drawings, the unit 6 represents a steam heated radiator, but a hot water or electrically heated unit cool l he used equally well in most. in:-:tan'c:-i;. ll urthermore, the supply of the heating medium to this unit is may 1' 2 automatically controlled. It is to be understood that reasonable va in the size, arrangement, and CQllllQCb in or the several dampers are within the scope of this invention, but the control of the opera tion of the trn 5 and the nature and control of the heating medium supplied to the unit 6 do not form a part of l hweution and their service connections, whicn may be of any usual or desired form, are not shown.

Dampers and 8 are shown pivotally supported at 9 and 10, respectively, and are operativcly connected to each other, by the link 11, and to the operating lever 12 ot' a liuidpressure motor 1?, by the link A spring 15 acts upon lever 12 to bppose the movement thereof by motor 13. T dB-111Gb 7." 13 is connected to be controlled in operation by the compound thermostatic controller 16, through the control-conduit l7. Dampers 18 and 19 are shown as pivotally supported at 20 and 21, respectively, and are ope zitively connected to each other, by the link 22, ing lever 23 of a fluir pressure motor by the link A spring 26 acts upon lever 23 to oppose the movement thereof by motor The motor 2-1: is connected to be controlled in operation by the controller 16, through. the control-conduit 27.

Damper 7 controls the outputoit air which passes through the heatu-adiating unit 6 and damper 8 controls the output of air whic by-passed around said unit (5, while da 18 controls an inlet 28 for admitting cold or fresh air and damper controls an inlet :tor admitting air from the lower part of the room for re-circulation. It will thus be seen that, with this rrangeineut, the operation of the several dampers will control the output of heated air as well as th admission of cold i air,

without icstristing the circulation. l urthernun'e,res emperirc less of the ature of the room, the circulation of air may be increased by employing the tan 5. needless to descril e the ir variations and wide range ol etlects which may be obta ned through the use and relative a jii tnicnts of the tow elements already men ned. but it is important to note that proper automatic it is aions and to the opera? control of these same elements provides for within the room, while allowing for excessive Variations in weather conditions.

In Fig. l, the interior of the *asing 30 of the air conditioning and circulating unit therein shown is divided into two communieating chambers, 31 and 32. T he output chamber 31 constitutes a mixing chamber into which the heated and unhe. Led air is controllably delivered the same as in chamber 2 of the previously described construction of Fig. 3, but the intake chamber differs from the chamber 4 of said previously described construction. This chamber is provided with a cold or fresh air inlet but not with a re-circulating air inlet. Instead of re-circulating and re-heatin g air taken from the lower part of the room, as in the previously de scribed construction of Fig. 8, it separately placed, supplemental heat-radiating unit i-l-l is arr: nged and controlled in operation to provide substantially, but not identically, similar effects. An electrically driven suction-tan 35 is shown arranged within the intake chamber 32 to serve the some purposes as those mentioned in connection with the tan 5 of Fig. 3.

Dampers 36 and 3'? are shown as pivotally suiported at 38 and 39, respectively, and are operatively connec'ed with each other, by the link ll), and to the operating lever ll of a fluid-pressure motor by the link 13. Damper 36 controls the output of air which passes through the heat-radiating unit at,

movement thereof by motor 42. The motor 42 is connected to be controlled in operatimi by the controller 18, through the controlconduit 17,

The supplemental heat-radiating unit 3st is'here shown as a conventional steam-heated radiator, but another type oi? heat-radiating unit could be substituted, if preferred. The supply oi the heating medium to this units controlled by a fluid-pressure motor loiatcd within the housing 46, which motor may be similar in construction and operation to the motor 42. This motor for 'oi'itrolliug he supply or the heating medium to the heatradiating unit 34 is connected to be controlled in operation by the controller 16, through the control-conduit 27. I

The operation oi the parts thus far described is as follows In the construction shown in Fi 3, alternate supply and release of thud-pressure through conduits 17 and 27 will eltcct the or cspouding' expansion and collapse of motors l3 and 24., respectively. Such supply and release of fluid-pressure through saidv conduits is autornatically controlled lt f'l'llf, compound thermostatic controller 16 in a manner to be presently described, it being suflicient at this point to state that, when thecontroller 16 has been set to effect and maintain a desired degree of temperature, the automatic controlling operation is such that increases in tempera ture slightly above saiddegree will occasion the aforesaid supply, and decreases in tem perature slightly below said degrcewill occasion the aforesaid release, of fluid-pressure through the conduits 1'? and 27.

The drawings show motor 13 and 2% as collapsed and the several dampers, Z, 8, 18 and 19, so positioned that the unit will opera-tote its em. heating capacity, the entire intake be ing that oi? partiallywarmed air drawn from the lower part of the-room through inlet 29,

and the entire output being; that of re-heatec, or superheated, air passed between the coils or" heat-radiating unit 6. When the temper ture of the room has increased to a predetermined degree, fluid-pressure will besupplied, through conduits 17 an d 27, to motors 13 and 2l, respectively. Motor 18 will be thereby ere pended, moving lever 12, against the opposition of spring 15, to eilect the openi: oil" damper 8 and the closing of dan'iper 7, through links let and 11, respectively, thus increasing the amount of air by-passed around the unit 6 and decreasing; the amount o'l air passed between the coils of said unit into chamber 2, and th nce outwardly into the room. ll lotor 2 1 will likewlse be expanded, moving lever 28, against the opposition of spring 26, to effectthe opening of damper 18 ZLBCll-lle closing; ofdamper 19, through links 22'and25, respectively, thus increasing IhG'LlIlOlllliof cold or fresh air admitted through inlet 28 and decreasing the amount of partially warmed air drawn from the lower part of the room through inlet 29.

In the construction shown in -l, the alternate supply and release or fluid-pressure through conduits 17 and 2'? will efi ect the corresponding expansion and collapse of motor 42 and the motor within housing 46, respectively, and such supply and release of fluid-pressure is automatically controlled by the controller 16 in the same manner as that previously described in connection with the controller 16 of Fig. 3. The drawings here show motor L2 as collapsed and it is to be assumed that the motor within housing 46 is also collapsed. Dampers 36 and 37 are shown positioned so that the air conditioning and circulating unit will operate to its full heat ing capacity, and it is to be understood that the collapse of the motor within housing d6 has effected toe supply ofthe heating medium to supplemental unit 34 so that it is operating to its full heat-radiating capacity. l/Vhenthe temperature of the room has increased to a predetermined degree, fluid-pressure will be supplied, through conduits 11'' and 2?", to motor a2 and the motor. within housing e6. Motor 42 will be thereby expanded, moving leverll, against the opposition of spring to edect the opening of damper 37 and the closing of damper 36, through links 4:3 and ldrespectively, thus increasing the amount of air lay-passed around the heat-radiating unit i land decreasing the amount o'l air passed' between the coils of said unit into chamber 51, and thence outwardly into the room. The motor within housing; is will likewise be expanded and shut oil the/supply of: the heating medium to supplemental unit is needless to describe, in detail, the return of t 0 several parts to their positions as shown in drawing it being sui'licient to to that, when the tenmerature oil the room decreased to a predetermined degree,tlie

sure of the steam in thesupply-pipe.

l' v hila as hereinbe'iore stated, the employment of the ans 5 and 35 do not form a part of this inv tention to the fact that the el'ficiency oil both types of air conditioning and circulating unite here" shown may augmented thereby. In the construction shown in Fig; 3,

both the air-heating and ai cooling "funcone of the unit may be materially increased by employing a forced draft, and this is so, in somewhat lesser degree, with the construction shown in 4;. With both constructions, should the direction of the wind be such as to interior-e with the properintake of fresh out-door air, the suction-fan could be used to correct such a condition.

Referring, now, to Figs, 1 and 2, the compound thcrinostatic controller therein shown is the element indicated at 16 in and at 16 in Fl kl; For convenience in descrip tion, the rollowing; detailed explanation of the construction and operation of the controller will refer to it opt tive association with the elements shown in S. butit is to be understood that all oi its parts function in exactly the same manner when it is operatively associated with the elements shown in The controllerlti mosoa ically actuated valve 4"? the supply and release. of

comprises a single theriuid-pressure to and from the two individual control-conduits 1'? and 2?. Fluid-pressure is supplied to the controher, thror a supply-conduit from a source not shownywhich may be suitably ltvplCSSlll'fi will be automatically released,

"ected by the valve-opening prision, it may be well to direct at which controls .lllU

constructed and located as preierred. Ah though the supply and release of fluid-pressure to and from the two conduits 1' and 27 is controlled by the single valve l7, such supply and release is effected gradually with respect to conduit 17 and positively with respect to conduit 27, the result being that the motor 13 3), connected with conduit 17, will be correspondingly expanded and collapsed gradually and proportionately with increases and decreases in temperature, while the motor Q-l, connected with conduit 27, ill be correspondingly completely expanded and completely collapsed without such graduated and proportionate movement.

An end-n'iember, nerein shown as a base 49, is provided with cars 50 by which the con troller is secured in position, 1 Ql ily upright upon the wall of the room at a point distant li'roui the air condi being and circulating units and the heat ,diatine units which it is designed to opei tively control. Supported upon base ell} is a tube of material possessing high icicnt of expansion. Tube 51 is internal y threaded at each end-part thereot, one end being screwed up n a boss of base 49 and the other titted wi an end-member, herein shown as a screw= 53, having a eentrall arranged? l lice fitted with an adjusting screw 5 t, 4

preterred means may be employed tor ad .151 shown, the u ing the screw 5 As he pper end-part of the screw is squared and operatively engaged by a circular steel wrenchplate and wrench-plate is provided with a pair of uj'istanding pins .v-xlnch project through corresponding apertures in a superposed cap, or adjusting 57 is formed with a dependin 58 suitable to be eng: ed by the lingers tor adjustment and provided with a thermoi'netric scale to be used to troller for operation at d: grees of temperature.

plate Plate annular flange The lower end of sore 7 al. is cupped at to receive the upper pointed end ot a rod preferably formed oi material poss s low co-eliicient of expansion. A pt I ri dly supported by base to project 1 war within tube 51., and the upper en l part oi this post carries a ri idly lined orally extending arm tured at ($3 to receive and go l part of rod 60 and also Peri 1. to .aupport re valve l7 by means of the flat spring connce tion (i l, the upper and lower ends of which are respectively anchored in tbe'arin and. the valve 47. ln addition to serving as a support for valv $27, the spring connection (i l acts to yieldingly hold the valve .lOs vd over the port 65 and also tending arm 66, by which the resistance oi the spring connection may be OYH'C! e and the valve moved to open the port. Near its free end, the upper surface of arm (56 is provided carries a laterally e:-:-'

gitudinal contraction and expansion of the tube 51. As viewed in Fig. l, contraction oi the tube, which will be occasioned by a decrease in temperature, will draw plug 53 toward base ll), i 'trcing-rod (5O downwardly upon arm 66 and thereby flexing spring connection 6% and moving valve ll to open the port Conversely, expansion oi the tube. 51, which will be occasioned by an increase in temperature, will move plug 58 away from base a9; rod (30 vill remain at rest upon the arm (36, since the closed valve 4? prevents the spring connection 6% from raising said arm; and the cupped end of screw will be lifted away il'ron'i the upper end of the rod, the disc or spider 68 then serving to keep the rod prop-- erly positioned for ca-engagement with screw bl when it is lowered, either by a subsequent contraction of tube- 51 or by the adjustment of the screw in its threaded relation with plug 53 through n'iovenient of the adjusting plate Obviously, it a contraction of tube 51 has el'lected the opening of valve 482' in the manner j ust described, a subsequent expansion of thtube will first ellect the closing of the valve before the screw 54 will be lifted away from the upper end of the rod. However, under normal operating conditions, this described lifting of the screw away from the upper end of the rod 60 will not often occur, since the gradual closing oi the port 65 by valve l7 will be represented by corresponding adjustments in the air conditioning and heating apparatus controlled thereby, and in creases in the temperature would be arrested before reaching such a degree. Hot weather co1uliti n1sor a adical adjustment of plate 57 might etl'ect this do: ribed unusual result. but there would be no disarrangeinent oi any of the parts. Jnder ideal vice ndi ons, valve 4'7 will be maintained in a state or floating equilibrium ov port {55, acting to control the amount oi fluid-pres 'e allowed to escape therefrom at d thus govern the degree of fluidpressuresupplied to conduit l"? in ma nn-cr to be presently more tally explained.

l l ithin base a suppl duct (39 extends from supply-conduit 48 an d is cornieeted with two passages 70 and 71, the connection with these passages being controlled, respectively, by adjustable needle-valves '2'2 and 73. Passage '50 connects with an outlet-duct i l, a control-duct 75, and a passage 76. Outlet-duct 74- leads to port through a vertically extending passage 7?, provided in the lower end-part of post 61, and a laterally extending outlet 78 in the nozzle 79. Control-duct 7 leads directly to conduit 17, and passage '76 terminates in a port opening upon the upwardly presented face of aboss 80, which is centrally arranged in a recess or chamber beneath a flexible diaphragm 81. Passage 71 connects with a short vertically extending passage 82, the lower end of which terminates in a port opening upon the downwardly pre sented face oil a boss 88, which is centrally arranged in a recess or chamber above diaphragm 81, and the upper endoi passage 82 connects with a laterally extending controlduct8 l leading directly to conduit 27. An 0utletduct 85 is provided in base as for venting the interior of tube/51 to the outer airfand an outlet-duct 86 vents the annular recessor chamber surrounding boss 83 above diaphragm 81. l

Needle-valve 72 is designed to be adjusted so that the amount of fluid-pressure permitted to pass to its respective ducts and passages, and to the recess or chamber beneath dia phragm 81 and conduit 17, will not equal the amount which valve 47, when fully open, will" allow to escape from port 65 aud t-hence,

through outlet-duct 85, to the outer air, and needle-valve73 is likewise designed to headjustedlso that the amount of fluid-pressure permitted-by it to pass to its respective duct and passages, and to the recess or chamber above diaphragm 81 and conduit 27, will not equal the amount which diaphragm 81, when lowered as shownin Fig-.1, willallow to escape from the lower end of passage 82 and thence, throughoutlet-duct 86, to the outer air.

With the parts positioned shownin Fig. 1, it isto be assumed forth'e moment that fluid-pressure is not being supplied to the system. The closed position oit'valve l7 over port indicates, however, that the temperature of he room is slightly above the degree for which the controller has been set, tube 51 having expanded suflicientlyto e'l'lect such closure but not enough to have lifted screw 54 away from the upper end o'frod 6O. Upon the supply or fluid'pressure through supplyconduit 48 to supply-duct 1 amount will pass needle-valve 73 into "passage 71, to passage 82,out through the port in boss 88, over diaphragm 81, and out to the atmosphere through out-let duct '86. This escape of fluid-pressure from the open lower" end of passage 82 prevents any accumulation of pressure in the laterally extending control duct 84 connected with the upper end ofpas- 7, amount of fluid-pressure will also pass n'eedlesage 82 and leadingtovconduit 27. A limited valveZQ, into passage 70, but will be prevented from escapingthrough outlet duct 7 t, passage 77., an d out-let 7 8, since port 65 is closedby valve 1 at, and pressure will begin to accumulate in controlduct 7,5" and conduit 17, and also in mat-1e .ll/L motor a J, A: o e

passage Z6. as the pressure accumuh lilig; .8) istherehy thereof shown inFig. the a:

position of diaphragm 81 seals the compare tively small-terminal port of passage '76 in v the boss and, since the entireupper surl aceei": the diaphragm is exposed to theeilect or the iluidpressure which is passing from passage 8:2 to outlet duct 88, the diaphragm will be mainta ned in such lowered position until sufficient pressure has accumulated in i "sage/Z6 to slightly lift the centre of the i pnragm. its soon as this occurs, the fluidpressure in p 76 will extend to the annu larfrecess or chan'iber surrounding boss 80' and, actingthen uponthe entire lower "sun,

i -ace oi the diaphrgam, will force thediaphragniagainst boss 88, instantly stopping the escape of fluid-pressure from passage 82 to outlet-duct 86. Pressure now begins'to accumulate in passage 82, control-duct 84-, and- Ccond'uit 27 and, as it accumulates, motor 2d (Fig 1s therebyentirely expanded and 'daniper'18 closed and 19 open recirculating in room. From theforegoing descrip'-' t1on,j1t will be 'seenfthat', with thevalve 47 I completely closechther'e will be an appre' cia le length, of time between the periods at p which pressure begins" to accumulate in the two conduits 1'Z'and2i'; that is to say,'there in conduit 17 to effect the operation of diaplnragnrr ll and stop the escape of fluid-pres sure through outlet-duct 86 before pressure lcan begin'to accumulate in -conduit 27. It

will also be noted th'atthe' speed with which pressure may accumulate in each "of said conduits may be definitely adgusted for each conduit by the respective needle-ValVesZQand 7 If port 65 had been. partly opeinit would have delayed the described accumulation or presmust be a sufficient accumulation ofpressure sure in conduit 17 and thereby have slowed I up theexpansion of motor-l8-a'ndthe opera- 'tlOIlOi' diaphragm 81. Such delay, in thc operation of diaphragm 81 would hayesiinn larly delayed the period'at'whicl'i pressure 69 a limited began toaccumulate incondmt 27, othat,

1 withthe needle valves properly adjusted with relation'to each other and theeinployment oi a sullici1ently sensitive inc-tor18, a consider-- "ableadpistinent ct dampers 7 and ,8 may be 7 obtained before, and even without, occasion ing the operation of motor 24 and the consequent adjustment of dampers 18 and'l'S;

I Returning, new, tothe description of the thermostaticoperation of the controller 16 and assunnngthat motors l3 and 24 have been of fluid-pressure to the'respective conduits 1'? completely expanded by the aforesaid supply and 27, the temperature of the room will be gin to decrease, due to the cooling effect produced by the reversed positions ofall'o'f the dampers7, 8,18 and 19, fron'ithe positions in passage perature thus decreases, tube 51 of the controller will contract and force rod 60 downwardly upon the extending end of arm 66, flex spring connection 6ft and begin the opening of valve 47. The slighest opening of port 6.5 by this opening movement of valve 47 will weaken the degree of pressure in conduit 17 and be represented by a corresponding partial collapse of motor 13 and adjustment of dampers 7 and 8, but will not at first sufficiently weaken the pressure beneath diaphragm 81 to allow it to uncover the terminal port of passage 82 in boss 83, the pressure applied beneath the diaphragm acting upon its entire under surface, while the opposing effect of the pressure in passage 82 is at this time exerted only upon the comparatively small area of the upper surface of the diaphragm actually covering the terminal port of passage 82 in boss 83. It is thus evident thata considerable reduction of pressure may occur in conduit 17 before the fluid-pressure in conduit2i' begins to be released, and it follows thatmotor 13 Fig. 3 ma collaase and adjust dampers i and 8 to a considerable extent before motor 2 1 will be permitted to collapse and change the adjustment of dampers 18 and 19 at all.

Under normal weather and heating conditions, it is to be presumed that at some point in the opening of port 65, valve 47 will become somewhat stabilized in position, allowing enough of the fluid-pressure passing needlevalve 72 to escape from port ($5 to maintain motor 13 and dampers 'Z and 8 in intermediate positions of adjustment. Should the room temperature continue to decrease, tube 51 will be correspondingly further contracted, valve l? will be further opened, and dampers 7 and 8 further adjusted to increase the amount of air passed through heat-radiating unit 6 and decrease the amount of air bypassed around said unit. When the pressure 76 has been weakened by this further oiiening of valve 47 to a degree at which it can no longer hold diaphragm 81 against the opposing action of the accumulated pressure in passage 82, the diaphragm will drop and allow the fluid-pressure in passage 82 to escape over the diaphragm and out through outlet duct 86, resulting. in the release of fluid-pressure from conduit 27 and the collapse of motor 24, thereby restoring dampers 18 and 19 to their positions shown in Fig. 3. This dropping of diaphragm 81 will be accelerated by the action of the accumulated pressure in passage 82 extending over the entire upper surface of the diaphragm, and the diaphragm will be moved positively into its lowered position, as shown in Fig. 1, sealing the terminal port of passage 76 in the boss 80.

As hereinbefore stated, the controller 18? and conduits 17 and 2-7 of Fig. 4; are identical in all respects with the controller 16 and conduits 17 and 27 of Fig. 3, just described. Motor 4-2 and the motor in housing operate and are controlled in operation in the same manner as are motors 13 and 2 1, respectively, and it follows that the control of dampers 36 and 37 will be the same as that of damoers 7 and 8, while the automatic admission and shutting off of the heating medium to heat radiating unit 8% will be occasioned in the sameiinanuer as that described in connection with the adjustment of dampers 18 and 19. The modified arrangement of Fig. 4 may be more desirable in some locations and under certain circumstances and conditions, but the application of compound thermostatic control of the elements therein illustrated is the same as described in connectionwith the elements illustrated in Fig. 3.

It has been pointed out that there will be an appreciable length of time between the periods at which pit sure begins to accumulate in the two conduits 17 and 27, and that a considerable adjustment of dampers 7 and 8 may be'obtained before, and even without, occasioning the operation of motor 24: and the consequent adjustment of dampers 18'and 19. it has also been mentioned and shown that a conside able reduction of pressure may occur in conduit 17 before the pressure in conduit 2? begins to be released, and that dampers and 8 may be adjusted to a considerable extent before motor 24: will be permitted to collapse and change the adjustment of dampers 18 and 19 at all.

This delay in the supply and release of fluid-pressure in conduit 2'? has an important bearing in the operation of the system, which may perhaps be more readily understoodby referring to Fig. i, wherein the sepantely placed supplemental heat-radiating unit 3 1 is shown as controlled through conduit 2? and, in this respect, takes the place of dampers 18 and 19 controlled through the conduit 27 of Fig. 3. As its name implies, the supplemental unit SM is employed an auxiliary element, or booster, to assistthe air-heating capacity of the air conditioning and circulatiug unit, andthe same maybe said'of the employement of dampers 18 and 19. l hen the room temperature decreases and the consequent automatic adjustn'ient of the dampers controlled through conduit 17 3) or 17' (Fig.4), does not arrest such decrease in temperature, the dampers 18 and 19 (Fig. 3),

or the sujiiplement-al heat-radiating uni; 3 1

automatically adjusted to arrest such increase and, if "their adjustment will not suiliciently counteractthe additional heating assistance 7 a provlded by the prevlous adJustment or tially stabilized floating position over port (35, serving normally to determine the amount of fluid-pressure to be allowed to escape from port and thus maintain a substantially even temperature by slight adjustments of the dampers constrolled through conduit 17, or 17, bringing in the additional service controlled through conduit 2'7, or 27', only when normal conditions are disturbed and are to be restored. i V While l have described but two embodiments of my invention, it is obvious that many modifications therein may occur to those skilled in the art, and I desire, therefore, that my invention be limited only bythe scope'ol the appended claims and by the prior art; lclaini: V y

l. A thermostatic controller comprisinga thermally expansible and 'cont'ra c'tible tube, a member secured to one end-part ot'said tube, a fluid-pressure supply-conduit and a plurality oif fluid-pressure control-conduits connected with said member, a supply-duct and a plurality of control-ducts in-said member connected respectively with said supply-conduit and said control-conduits, passages individually connecting said supply-duct with said control ducts, individually adjustable means restricting the passage of 'i'iuid-pres sure from said suf 'Jply-duct to each of said passages, outlet-ducts individually connected with a first and a second of said passages and terminating in first and second outlet-ports,

respectively, a first valve actuated by the expansion and contraction of said tube to ellect a proportionately graduated control of said first outlet-port, a second valve actuated by fluid-pressure to effect the control of said sec- 0nd outlet-port, and apassage connecting said second valve with said first of said passagesj 2. A thern'iostatio controller comprising a thermally 'expansible and contractible tube,

the elemei'its controlled through a member secured to one end-part of said tube, a fluid-pressure supply-conduit and a plurality of fluid-pressure control-conduits connected with said member, a supply-duct and a plurality of control-ducts in said member connected respectively with said supply-conduit and said control-conduits, passages individually connecting said sup'plyduct with said control-ducts, individually adjustable means restricting the passage of fluid-pressure from said supply-duct to each of said passages, outlet-ducts individually connected with a first and a second of said passages'and terminating in first and second outlet-ports, respectively, a first valve actuated by the expansion and contraction of said tube'to cited; a proportionately graduated control of said first outlet-port, a diaphragm-valve actuated byiiuid-pressure to control said second outlet-port, a sealed chamber of which said diaphragmvalve forn sa flexible wall, and a passage connecting said chamber with said lirst of said passages. 3. A thermostatic construction for controlling t wo fluid-pressure motors, comprising an air passage for communicationwith the pressure supply, two restricted branch passages leading from said pressure passage, an exhaust port and a passage leading to one ol said pressure motors, both, said exhaust port and said passage being in connnunicationwith. one of said branch passages whereby when said exhaust port 1s closed said pressure motor will be expanded and whereby when said exhaust port is open said pressure motor willbe exhausted, a thermostatic valve for controlling said exhaustp'ort, another exhaust port and a passage leading to the other pressure motor, both said other exhaust port and saidpassage beingin co1nmunication with the other of said branch passages, whereby when said exhaust passage is closed said pressure motor will be expanded and whereby whensaid exhaust port is open said pressure motor will be exhausted, and a motor device controlled by the pressure in said one olrsaid branch passages for controlling the exhaust from the exhaust port for said other oi saidbranch passages, and means whereby an increase or temperature causes the thermo-- static valve to close. I

In witness whereof, I have hereunto subscribed my name. i

. o JOHN M. LARSON; 

